Re: [Patch] debugfs: remove module_exit()

[Cong Wang <amwang@redhat.com>]

On 12/01/10 09:35, Greg KH wrote:
> On Tue, Nov 09, 2010 at 04:19:58AM -0500, Amerigo Wang wrote:
>> debugfs can't be a module, so module_exit() is meaningless
>> for it.
>>
>> Signed-off-by: WANG Cong<amwang@redhat.com>
>>
>> ---
>> diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
>> index 37a8ca7..d38c88f 100644
>> --- a/fs/debugfs/inode.c
>> +++ b/fs/debugfs/inode.c
>> @@ -13,9 +13,6 @@
>>    *
>>    */
>>
>> -/* uncomment to get debug messages from the debug filesystem, ah the irony. */
>> -/* #define DEBUG */
>
> Why did you remove these lines?  They don't pertain to this patch.

These lines are obsolete.


>
>> -
>>   #include<linux/module.h>
>>   #include<linux/fs.h>
>>   #include<linux/mount.h>
>> @@ -540,17 +537,5 @@ static int __init debugfs_init(void)
>>
>>   	return retval;
>>   }
>> -
>> -static void __exit debugfs_exit(void)
>> -{
>> -	debugfs_registered = false;
>> -
>> -	simple_release_fs(&debugfs_mount,&debugfs_mount_count);
>> -	unregister_filesystem(&debug_fs_type);
>> -	kobject_put(debug_kobj);
>> -}
>
> When the code is built into the kernel, the __exit function should go
> away, so this isn't costing us any extra memory, right?


Perhaps, but this can still reduce the vmlinux size, right?

>
> And debugfs used to be able to be built as a module, perhaps it will be
> in the future?  I don't think this patch is really needed.
>

Huh? Wasn't it a module before?

I think the problem is tracers use debugfs, it needs to depends on DEBUGFS=y.

Thanks.